2 9 of of Percents Applications Percents 2

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2 -9 of of Percents Applications Percents 2 -9 Application Warm Up Lesson Presentation

2 -9 of of Percents Applications Percents 2 -9 Application Warm Up Lesson Presentation Lesson Quiz Holt Algebra 1

2 -9 Application of Percents Warm Up 1. Write 0. 03 as a percent.

2 -9 Application of Percents Warm Up 1. Write 0. 03 as a percent. 3% 2. Write as a decimal. 0. 045 Find each value. Round to the nearest tenth if necessary. 3. Find 10% of 53. 5. 3 4. Find of 50. 1. 25 Solve for x. 5. 40 = (x) Holt Algebra 1 (20) 4 6. 114 = (36) (x) 38

2 -9 Application of Percents Objectives Use common applications of percents. Estimate with percents.

2 -9 Application of Percents Objectives Use common applications of percents. Estimate with percents. Holt Algebra 1

2 -9 Application of Percents Vocabulary commission interest sales tax principal tip Holt Algebra

2 -9 Application of Percents Vocabulary commission interest sales tax principal tip Holt Algebra 1

2 -9 Application of Percents A commission is money paid to a person or

2 -9 Application of Percents A commission is money paid to a person or a company for making a sale. Usually the commission is a percent of the sale amount. Holt Algebra 1

2 -9 Application of Percents Caution! You must convert a percent to a decimal

2 -9 Application of Percents Caution! You must convert a percent to a decimal or a fraction before doing any calculations with it. Holt Algebra 1

2 -9 Application of Percents Example 1: Business Application Mr. Cortez earns a base

2 -9 Application of Percents Example 1: Business Application Mr. Cortez earns a base salary of $26, 000 plus a sales commission of 5%. His total sales for one year were $300, 000. Find his total pay for the year. total pay = base salary + commission Write the formula for total pay. the formula = base + %Write of total sales for commission. = 26, 000 Substitute + 5% of 300, 000 values given in the problem. the percent as a decimal. = 26, 000 + Write (0. 05)(300, 000) = 26, 000 + 15, 000 Multiply. = 41, 000 Add. Mr. Cortez’s total pay was $41, 000. Holt Algebra 1

2 -9 Application of Percents Check It Out! Example 1 A telemarketer earns $350

2 -9 Application of Percents Check It Out! Example 1 A telemarketer earns $350 per week plus 12% commission on sales. Find her total pay for a week in which her sales were $940. total pay = base salary + commission Write the formula for total pay. the formula = base + %Write of total sales for commission. = 350 + 12% of 940 Substitute values given in the problem. Write the percent as a decimal. = 350 + (0. 12)(940) = 350 + 112. 80 Multiply. = 462. 80 Add. The telemarketer’s total pay was $462. 80. Holt Algebra 1

2 -9 Application of Percents Interest is the amount of money charged for borrowing

2 -9 Application of Percents Interest is the amount of money charged for borrowing money, or the amount of money earned when saving or investing money. Principal is the amount borrowed or invested. Simple interest is interest paid only on the principal. Simple Interest Paid Annually Time in years Simple interest Principal Holt Algebra 1 Interest rate per year as a decimal

2 -9 Application of Percents Example 2 A: Financial Application Find the simple interest

2 -9 Application of Percents Example 2 A: Financial Application Find the simple interest paid for 3 years on a $2500 loan at 11. 5% per year. I = Prt I = (2500)(0. 115)(3) I = 862. 50 Write the formula for simple interest. Substitute known values. Write the interest rate as a decimal. Multiply. The amount of interest is $862. 50. Holt Algebra 1

2 -9 Application of Percents Example 2 B: Financial Application After 6 months, the

2 -9 Application of Percents Example 2 B: Financial Application After 6 months, the simple interest earned on an investment of $5000 was $45. Find the interest rate. Write the formula for simple I = Prt interest. Substitute the given values. 45 = 2500 r 0. 018 = r The interest rate is 1. 8%. Holt Algebra 1 Multiply 5000. . Since r is multiplied by 2500, divide both sides by 2500 to undo the multiplication.

2 -9 Application of Percents Helpful Hint When you are using the formula I=

2 -9 Application of Percents Helpful Hint When you are using the formula I= Prt to find simple interest paid annually, t represents time in years. One month is Holt Algebra 1 year.

2 -9 Application of Percents Check It Out! Example 2 a Find the simple

2 -9 Application of Percents Check It Out! Example 2 a Find the simple interest earned after 2 years on an investment of $3000 at 4. 5% interest earned annually. I = Prt Write the formula for simple interest. I = (3000)(0. 045)(2) Substitute the given values. I = 270 Multiply. The interest earned is $270. Holt Algebra 1

2 -9 Application of Percents Check It Out! Example 2 b The simple interest

2 -9 Application of Percents Check It Out! Example 2 b The simple interest paid on a loan after 6 months was $306. The annual interest rate was 8%. Find the principal. I = Prt 306 = (P)(0. 08) 306 =. 04 P Write the formula for simple interest. Substitute the given values. Multiply 0. 08. Since P is multiplied by 0. 04 , divide both sides by 0. 04. 7650 = P The remaining principal is $7650. Holt Algebra 1

2 -9 Application of Percents A tip is an amount of money added to

2 -9 Application of Percents A tip is an amount of money added to a bill for service. it is usually a percent of the bill before sales tax is added. Sales tax is a percent of an item’s cost. Holt Algebra 1

2 -9 Application of Percents Sales tax and tips are sometimes estimated instead of

2 -9 Application of Percents Sales tax and tips are sometimes estimated instead of calculated exactly. When estimating percents, use percents that you can calculate mentally. • Find 10% of a number by moving the decimal point one place to the left. • Find 1% of a number by moving the decimal point two places to the left. • Find 5% of a number by finding of the number. Holt Algebra 1 of 10%

2 -9 Application of Percents Example 3 A: Estimating with Percents Lunch at a

2 -9 Application of Percents Example 3 A: Estimating with Percents Lunch at a restaurant is $27. 88. Estimate a 15% tip. Step 1 First round $27. 88 to $30. Step 2 Think: 15% = 10% + 5% Move the decimal point one place left. 10% of $30 = $3. 00 Step 3 Think 5% = 10% ÷ 2 = $3. 00 ÷ 2 = $1. 50 Step 4 15 = 10% + 5% = $3. 00 + $1. 50 = $4. 50 The tip should be about $4. 50. Holt Algebra 1

2 -9 Application of Percents Example 3 B: Estimating with Percents The sales tax

2 -9 Application of Percents Example 3 B: Estimating with Percents The sales tax rate is 7. 25%. Estimate the sales tax on a book that costs $19. 97. Step 1 First round 7. 25% to 7% and $19. 97 to $20. Step 2 Think: 7% = 7(1%) 1% of $20 =$0. 20 Step 3 7% = 7(1%) = 7($0. 20) = $1. 40 The sales tax is about $1. 40. Holt Algebra 1 Move the decimal point two places left.

2 -9 Application of Percents Helpful Hint A 6. 25% sales tax rate means

2 -9 Application of Percents Helpful Hint A 6. 25% sales tax rate means that for every $100 you spend, you would pay $6. 25 in sales tax. Holt Algebra 1

2 -9 Application of Percents Check It Out! Example 3 a Estimate a 15%

2 -9 Application of Percents Check It Out! Example 3 a Estimate a 15% tip on a check for $21. 98. Step 1 Think: 15% = 10% + 5% 10% of $22 = $2. 20 Move the decimal point one place left. Step 2 Think 5% = 10% ÷ 2 $2. 20 ÷ 2 = $1. 10 Step 3 15% = 10% +5% = $2. 20 + $1. 10 = $3. 30 The tip should be about $3. 30. Holt Algebra 1

2 -9 Application of Percents Check It Out! Example 3 b Estimate the tax

2 -9 Application of Percents Check It Out! Example 3 b Estimate the tax on shoes that cost $68. 50 when the sales tax rate is 8. 25%. Step 1 First round 8. 25% to 8% and $68. 50 to $70. Step 2 Think: 8% = 8(1%) 1% of $70 =$0. 70 Step 3 8% = 8(1%) = 8($0. 70) = $5. 60 The sales tax is about $5. 60. Holt Algebra 1 Move the decimal point two places left.

2 -9 Application of Percents Lesson Quiz: Part 1 1. A computer salesperson earns

2 -9 Application of Percents Lesson Quiz: Part 1 1. A computer salesperson earns a base salary of $32, 000 per year plus a commission of 6% on total sales. Total sales for one year were $350, 000. Find the salesperson’s total pay for the year. $53, 000 2. Find the simple interest paid for 9 months on a a $500 loan at 8% per year. $30 3. After 2 years the simple interest earned on an investment of 4000 was $216. Find the interest rate. 2. 7% Holt Algebra 1

2 -9 Application of Percents Lesson Quiz: Part 2 4. A family’s dinner check

2 -9 Application of Percents Lesson Quiz: Part 2 4. A family’s dinner check was $38. 82. Estimate a 15% tip. About $6. 00 5. The sales tax rate is 7. 1%. Estimate the sales tax on a television set that costs $399. About $28 Holt Algebra 1